Liquid fuel injection nozzle units



y 1970 P. E. GLlKlN ET AL 3,511,443-

I LIQUID FUEL INJECTION NOZZLE UNITS Filed May a, 1968 -22 25 L, 1/ 1; X\ 20 J- 2 \e we 52.

l5 JL. /4 2 318 Z' *3 INV NT 4.2.2) 52. 23 2 BY flaunk. ATTORNEYS United States Patent LIQUID FUEL INJECTION NOZZLE UNITS Paul Edgar Glikin, Hendon Way, London,-and John Richard Bishop, Staines, Middlesex, England, assignors to (LAN. Limited, London, England, a British com- Filed May 8, 1968, Ser. No. 727,577 Claims priority, application Great Britain, May 23, 1967, 23,886/67 Int. Cl; Bb 1/30 US. Cl. 239--533 3 Claims ABSTRACT OF THE DISCLOSURE This invention relates to liquid fuel injection. nozzle units of the kind comprising an elongated body havingmounted or secured at one end thereof a nozzle head in which is formed an orifice, a seating defined in said head, an axiallymovable valve member extending within a bore defined in the body, one end of said valve member being shaped for oo-operation with said seating and a guide bush located with an enlarged portion of the bore at the end thereof remote from said one end of the valve member for guiding the movement of said valve member.

The object of the invention is to .provide such a nozzle unit in a simple and convenient form.

According to the invention in a nozzle unit of the kind specified the other end of said valve member is of reduced diameter and extends through an aperture formed in a stop plateengaged with the body, the stop plate co-operating with the step defined on the valve member to limit the axial movement of the valve member away frbm the seating, and there is provided intermediate said stop plate and the bush a washer through which the bush is retained against axial movement, the thickness of the washer serving to, determine the axial movement of the valve member away from the seating.

In the accompanying drawings:

FIG. 1 is a sectional side elevation of one example of a fuel injection nozzle unit in accordance with the invention, and

FIG. 2 is a view similar to FIG. 1 showing a modified arrangement of part of the nozzle unit of FIG. 1.

As shown in FIG. 1 of the drawings the nozzle unit comprises an elongated generally cylindrical body 10, which at one end 13 is of reduced diameter and which intermediate its ends is provided with a lateral boss 11. Formed withinthe body is a stepped axially extending bore the narrower portion 14 of the bore extending from the boss to said one end of the body. An intermediate portion 15 of the bore extends a short distance from the boss 11 towards the other end of the body and a wider portion 16- of the bore extending from the intermediate portion to said other end of the body.

Located within the portions 15 and 16 of the bore is a flanged bush 17 which has its flange engaged against the step defined between the intermediate and Wider portions of the bore. The bush 17 is provided with an axial bore within which is mounted an elongated valve member 18 which extends with clearance through the portion 14 of the bore. Secured to the end 13 of the body is a nozzle head 19 which defines a seating with which cooperates the adjacent end of the valve member 18 in order to be able to control the flow of fuel through an orifice (not shown). The portion 14 of the bore is in communication with a liquid fuel inlet 20 and when the valve member is moved away from the seating fuel can flow from the inletto the orifice.

The valve member extends beyond the bush 17 and its end is of reduced diameter so as to define a step 21. Engaged with this end of the valve member is an abutment 22 for a coiled compression spring 23 which is located within the portion 16 of the bore and this portion of the bore is closed by means of a closurer member 24 which also serves as the other abutment of the spring.

The portion 16 of the bore is provided with a screw thread on its periphery and engaged within the bore is a stop plate 25 having an aperture formed therein through which the valve member extends. Moreover, located between the stop plate 25 and the flange of the bush is an annular washer 26.. The arrangement is such that fuel under pressure acting upon the valve member 18 moves the latter against the action of the coiled compression spring. The extent of movement is limited by abutment of the step 21 on the valve member, with the stop plate 25. The extent of movement of the valve member can be adjusted during assembly of thenozzle unit since this is determined by the thickness of the annular washer 26 which also serves to retain the flange of the bush 17 against the step defined between the portions 15 and 16 of the bore. During assembly the bush and valve member are inserted into the body and by means of a special gauge the distance between the step 21 on the valve member and the flange of the bush 17 is measured. The thickness of the washer which will be required to ensure the correct lift of the valve member is merely the distance measured as described plus the required lift. A suitable washer is inserted in the body and the stop plate is screwed into position.

It should be noted that the fit of the valve member within the bore formed in the bush should be good so as to reduce the leakage which would otherwise occur when fuel is admitted to the narrower portion of the bore. Since a certain seepage of fuel will occur a vent is provided from the wider portion of the bore.

In an alternative construction shown in FIG. 2 parts having the same shape and function are provided with the same reference numeral. In this construction however the bush 30 is not provided with a flange and it is held in position by the washer 26. Furthermore, the bush is urged into contact with the washer by means of a spring washer 31.

Having thus described our invention what we claim as new and desire to secure by Letters Patent is:

1. A liquid fuel injection nozzle unit of the kind specified comprising a body with a bore formed within said body, a stop plate having an aperture engaged with the body near its upper end, a valve member having an upper end of reduced diameter and forming a step on the valve member, said valve members reduced diameter portion extending through said aperture formed in said stop plate, the stop plate co-operating with said step on the valve member to limit the permitted upward axial movement of the valve member away from its seat, a bush positioned below and spaced from the stop plate, a washer intermediate said stop plate and said bush, the thickness of the washer serving to determine the permitted axial movement of the valve member away from the seating.

2. A nozzle unit as claimed in claim 1 in which the stop plate is screw threadedly engaged within said bore and acts to urge said 'washer into contact with one face of a flange defined on said bush, the other face of said flange being urged into contact with a step defined in said bore.

3. A nozzle unit as claimed in claim 1 in which the stop plate is screw threadedly engaged within said bore and acts to urge said washer into contact with a step defined in the bore, said bush being urged into contact with said washer by a resilient means.

4 References Cited UNITED STATES PATENTS 4/1945 Nichols 239533 X FOREIGN PATENTS 358,340 10/1931 Great Britain.

M. HENSON WOOD, JR., Primary Examiner J. I. LOVE, Assistant Examiner 

